Think of each class as a credit score. Individually they equal a result, but it's the combined average that counts.
ie: In the time of Jesus Christ's lifespan, he had a Class Bracket score of 600/1000 due to his high spiritual and social scores, but is dropped down significantly in the average because of his low economic score. Granted, he didn't care for money, but with it his influence could have been immediate, instead of hundreds of years later.